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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 25 cases (12 men, 13 women) of complete left bundle branch block (LBBB) were found among 1,400 consecutive autopsy in the aged. Their ages ranged from 70 to 86 years (average 78.9). ECG was analyzed as for the occurrence of LBBB and myocardial infarction (MI). Pathological examinations included observations of the conduction system by serial sections. They were divided into group A with MI and group B without MI. Duration of LBBB was 1 to 3 days in 4 cases, more than 1 month in 7, and more than 1 year in 14. From the temporal sequence of LBBB and MI in group A, cases were classified into (1) MI preceding LBBB in 5, (2) both coexistent in 5, and (3) LBBB preceding MI in 1. There were 8 cases of normal electrical axis, 17 left axis deviation, 7 first degree A-V block, and 2 atrial fibrillation. Various heart diseases were underlying in 21 cases, including hypertension, MI, mitral and aortic regurgitation, and primary myocardial disease, and there were 4 cases with no cardiac diseases. Cause of death was cardiac in 12; MI, congestive heart failure, and sudden death. Heart weight was 410 Gm on the average (240 to 550 Gm). MI was found in 11, with stenotic index of 12/15, while it was 9/15 in group B. Lesions of the conduction system were slight to moderate (1.5 to 2.4) except left bundle branch, which showed marked changes in posterior (4.9) and anterior (4.8) fascicles. Site of interruption of the left bundle branch was the junction between the branching portion of the A-V bundle and the left bundle branch (Junctional type) in 17, and peripheral portion of the left bundle branch about 10 mm or more below the junction in 8 (Peripheral type). In conclusion, 2/3 of cases of LBBB belonged to the junctional type and most of them were not related to MI, but to the lesions caused by mechanical injuries at the septal summit. One third of the cases were as peripheral type, which was mainly related to the various types of lesions including septal ischemia (necrosis and fibrosis).
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PMID:A clinicopathological study on 25 cases of complete left bundle branch block. 44 51

The experience with bundle branch block at the USAF School of Aerospace Medicine was reviewed. The clinical and follow-up status was evaluated in 394 subjects with right bundle branch block (RBBB) and 125 subjects with left bundle branch block (LBBB). The majority of subjects were asymptomatic at the time of bundle branch block diagnosis. The subjects were divided into subfroups based on electrocardiographic (EEG) findings to determine if any one subfroup was at higher risk for initial or follow-up morbidity of cardiobascular disease or follow-up mortality. At initial diagnosis and clinical evaluation, 94% of RBBB and 89% of LBBB subjects had no evidence of cardiobascular disease. In the RBBB group, 3 and 2% had cornary heart disease and hypertension, respectively; in LBBB subjects, 9 and 7% had cornary heart disease and hypertension, respectively. No one ECG subfroup in either the RBBB or LBBB group had a higher incidence of cardiobascular disease. Complete follow-up information was available in 94% of the RBBB subgroup subjects and 91% of the LBBB group. In the follow-up period, new cases of coronary heart disease and hypertension occurred in 6% of the RBBB group and 5 and 8%, respectively, in the LBBB group. Fourteen (4%) RBBB and nine (8%) LBBB subjects died during the follow-up period. No differences for follow-up groups. Progressive electrical dysfunction in the form of complete heart block occurred in one subject each absence, and degree of associated cardiobascular disease. Furthermore, within the age limits of the present aeromedical implications of bundle block are discussed.
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PMID:A clinical and follow-up study of right and left bundle branch block. 113 86

This phonocardiographic-echocardiographic study was based on measurement of the interval between the aortic component of the second sound (IIA) and the peak of the E wave of the mitral echogram. The study was performed in 20 cases of left bundle branch block (LBBB), 10 cases of right bundle branch block (RBBB), 10 cases of old myocardial infarct (MI), and 10 cases of systemic hypertension (HY). All patients were above 60 years of age, and their data were compared with those of old persons without evidence of heart disease serving as controls. The IIA-E interval was found markedly prolonged in LBBB, less prolonged in MI and RBBB, and was shortened in HY. A dynamic analysis revealed that this interval results from the isovolumic relaxation period (IRP) of the left ventricle plus the "opening time" of the mitral valve. The changes observed were explained as resulting from a modification of the IRP that should be correlated with a similar modification of the isovolumic contraction time. Myocardial fibrosis would cause prolongation of IRP through structural lesions while hypertension would cause abbreviation of IRP through hormonal effects modifying both contraction and relaxation.
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PMID:Ventricular relaxation and mitral opening time in various ventricular conditions of old age. 121 36

Thallium-201 exercise myocardial scintigraphy was performed in 57 patients (37 males, 20 females; mean age 55.4 [43-78] years) with angina and systemic hypertension after exclusion by coronary angiography of any coronary macroangiopathy. The exercise ECG of 32 patients could not be used in the diagnosis of ischaemia because of the presence of left ventricular hypertrophy with abnormal repolarization or left bundle branch block. Abnormal haemodynamics were demonstrated at cardiac catheterization in 23 patients (Swan-Ganz). Only 10 of the studied hypertensives with normal coronary angiograms had a myocardial scintigram within normal limits, while 12 had extensive ischaemic zones in the left ventricle. All patients with left bundle branch block had evidence of exercise-dependent apical "ischaemia". Thallium-201 myocardial scintigraphy should not be used as a screening method in hypertensives with angina, because the high proportion of "false-positive" findings, in the sense of a macroangiopathy, will nevertheless require early invasive diagnosis.
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PMID:[The importance of 201-thallium myocardial scintigraphy in the hypertensive patient]. 152 4

For the evaluation of myocardial perfusion in patients with left bundle branch block (LBBB), we performed exercise stress (Ex)-redistribution (RD) myocardial tomography with thallium-201 (201Tl) in 23 patients with LBBB and without coronary artery disease (CAD). Myocardial images in patients with LBBB were compared with those of 9 patients with CAD who showed Ex induced transient septal defect. Bull'-eye maps (201Tl distribution maps at Ex and RD and 201Tl washout rate [WOR] map) were made from myocardial tomograms. In 23 patients with LBBB, 15 patients (65%) developed myocardial perfusion abnormality. In 10 (67%) of these 15 patients, transient perfusion defect appeared in the entire septum (diffuse type). On the other hand in 5 patients (33%), localized fixed perfusion defect developed at the boundary between septum and anterior wall (focal type). In focal type, every patient had other disease such as hypertension, aortic stenosis or sick sinus syndrome. While in patients with diffuse type, other diseases were observed in 30% (p less than 0.05) and they were limited to hypertension or diabetes mellitus. These facts suggested that mechanisms of perfusion abnormalities might be different between these two groups. We compared the perfusion abnormality between LBBB diffuse type and CAD. The extent of the defects was not different between two groups. Although apex was included within the defect in 89% of CAD population, apical defect was observed in only 20% of diffuse type (p less than 0.05). Minimal 201Tl WOR and 201Tl uptake ratio of septum to lateral wall indicated that exercise induced septal defect was slighter in diffuse type than CAD.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Myocardial perfusion in patients with left bundle branch block and without coronary artery disease]. 160 38

A prospective study of electrocardiograms (ECG's) was carried out on 102 adult hypertensive African patients at the Kenyatta National Hospital. Their mean age was 45.2 years. All the patients had normal sinus rhythm. Forty seven percent of the patients had sinus bradycardia, although this could be attributable to the drugs they were taking. The duration of the P wave increased with the severity of hypertension. Twenty five percent of the patients had evidence of first degree A-V block. This was an expected finding as most of the patients were on treatment with B-adrenoreceptor blocking agents. Two patients had LBBB and none had RBBB. There were 13 patients with evidence of left axis deviation (LAD) and the incidence increased with the severity of hypertension. S-T, T changes were noted in 12.8% and 29% of patients respectively. Q-Tc duration did not increase with severity of hypertension. Left ventricular hypertrophy was noted in 27.5% of the patients using the criteria devised by Romhilt et al.
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PMID:A prospective study of electrocardiographic features in adult black hypertensive patients at the Kenyatta National Hospital, Nairobi. 168 72

The purpose of this study was to examine the time course and evaluate the clinical significance of marked left axis deviation (LAD) in airline pilots. The study group consisted of 30 Japan Airlines' pilots with marked LAD, identified from a group of 1,700 who are now 35 years of age or older. The mean age at examination was 48.5 +/- 5.7 years [corrected] and the mean observation period was 22.6 +/- 5.6 years [corrected]. The prevalence rate of marked LAD was 1.8%. In 20%, the axis remained unchanged, and in 70%, LAD progressed either gradually or suddenly. All subjects were examined by exercise testing and 26 had echocardiograms. Two pilots (6.7%) were found to have organic heart disease (hypertension), which was much lower than the rate reported previously. In these individuals, the onset of marked LAD was noted more than 10 years before hypertension was detected. No progression to complete left bundle branch block, nor any form of AV block, was observed among these subjects. No cardiac events or death occurred during the study period.
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PMID:Time course and clinical significance of marked left axis deviation in airline pilots. 189 6

Timely administration of thrombolytic therapy decreases myocardial infarct size, lessens the incidence of congestive heart failure and improves survival. However, available data suggest that only 10% of patients with acute infarction in the United States receive thrombolytic drugs. Given the benefits of thrombolytic therapy, all patients with myocardial infarction would likely be treated were it not for associated risks. Several groups exist in which the risk/benefit ratio of thrombolytic therapy continues to be controversial, including those with inferior infarction, absence of ST segment elevation or presentation greater than 6 h from symptom onset, elderly patients and those with hypertension. Three recent thrombolytic trials reported a reduction in mortality that was entirely independent of infarct location. Pooled data from trials involving 12,000 patients with inferior infarction have demonstrated a reduction in mortality rate (6.8% versus 8.7%, p less than 0.0001). Furthermore, improvement in regional and global left ventricular function occurred after reperfusion therapy of inferior infarction. Pooled data indicate that patients treated between 6 and 24 h after symptom onset have a lower mortality rate than do those who receive placebo (11.1% versus 13.1%, p less than 0.001). Improved survival occurs after thrombolytic therapy in patients with ST segment elevation or left bundle branch block, but not in those with isolated ST depression or a normal electrocardiogram. Age should not be considered an absolute contraindication because the lifesaving potential of thrombolytic therapy in the elderly may be two to three times that of the overall group of patients with myocardial infarction. Finally, recent studies demonstrated that patients who present with hypotension or hypertension or who have undergone cardiopulmonary resuscitation may also benefit.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Optimal utilization of thrombolytic therapy for acute myocardial infarction: concepts and controversies. 219 50

Nineteen patients with LBBB were studied by clinical, electrocardiographic (ECG), echocardiographic, electrophysiological and coronary angiographic examination. The commonest etiology of LBBB observed was idiopathic/degenerative in 10 (52.6%), followed by atherosclerotic coronary artery disease in 6 (31.5%) and hypertrophic cardiomyopathy, dilated cardiomyopathy and systemic hypertension in 1 case each (15.7%). In all patients with coronary artery disease (CAD), significant lesion of the left anterior descending artery was observed. On ECG, presence of Q in I, aVL, V5 or V6 was most helpful in predicting the presence of CAD while primary T-wave changes were least helpful. The degree of QRS axis was not helpful in predicting the presence as well as severity of CAD. Altered septal/regional wall motion abnormalities were commonly encountered on echocardiography and left ventriculography. Although infrahisian conduction delay was frequently observed and 11 (61.1%) had prolonged HV interval, in 2 of these there was additional suprahisian conduction delay. All patients with prolonged PR interval (more than or equal to 200 msec) or wide QRS duration (more than 140 msec) had infrahisian block with or without associated suprahisian block. Hence, hemodynamic evaluation, coronary angiographic studies and electrophysiological evaluation is essential in patients with LBBB.
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PMID:Noninvasive and invasive evaluation of left bundle branch block (LBBB). 233 87

The surface electrocardiogram remains an insensitive method for detection of ventricular hypertrophy. Technical problems related to body size and habitus and distance from the heart cannot be overcome. Coronary arterty disease and amyloidosis, although frequently associated with hypertrophy, tend to obscure the electrocardiographic changes because of the attendant loss of voltage. The progress made in the last 20 years is due primarily to re-evaluation of traditional criteria in terms of careful anatomic correlation. The studies cited have the advantage of using specific clinical diagnoses in a defined population, specific chamber weights, and a 97.5 percentile confidence level for distinguishing normal pathologic and electrocardiographic data from abnormal. They are limited because the results may not apply to females or patients with mitral stenosis and congenital heart disease. In general, the electrocardiogram can be expected to detect left ventricular hypertrophy in six out of ten patients with the disease, and will misdiagnose the problem in about one out of every ten without the disease. Methodology using multiple criteria will achieve the best sensitivity and specificity. Several methods are available and of comparable accuracy. Simplicity of these methods varies widely and will be a factor in the choice of the method selected. The electrocardiogram will perform best in the population of patients with hypertension and aortic stenosis or regurgitation and have its greatest limitation in patients with coronary artery disease and myocardial infarctions. Echocardiography is proven to be more sensitive than the electrocardiogram for detection of left ventricular hypertrophy. Sensitivity is around 90 per cent with 95 per cent specificity. Its major limitations lie in the expense as compared to the electrocardiogram and in inadequate image resolution in a small proportion of patients. In order to achieve the results reported by centers proficient in this technique, careful attention must be paid to precise standardization of measurements and selection of images to be measured. When this is done the echocardiogram certainly offers a distinct advantage over the electrocardiogram in detecting left ventricular hypertrophy. We recommend the use of left atrial abnormality as a criterion to diagnose left ventricular hypertrophy when there is right bundle branch block. When left bundle branch block is present on the electrocardiogram, traditional criteria are probably no more accurate than the bundle branch block itself.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Recent progress in the electrocardiographic diagnosis of ventricular hypertrophy. 296 47


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